This invention relates to a folding trailer more particularly to a large trailer that an individual would find difficult to stand up into the vertical position. The assistance of a winch or jack is used to enable one person to easily store the trailer from the towed position to the stored position. Fold up trailers have been disclosed previously such as that disclosed in U.S. Pat. Nos. 4,362,316 and 5,924,836. The present invention addresses limitations of each of these and provides a novel solution to simplify construction and allow a large and heavy trailer to be folded into an upright stored position.
The invention disclosed in U.S. Pat. No. 4,362,316 of Wright is most similar in structure to the present invention. A rear section of the load bearing surface folds over the axle to shorten the bed and the tongue portion folds downward as the trailer in moved into the vertical position. The tongue portion is itself foldable and rotatably connects to a point behind the rolling wheels of the trailer. This allows the operator to stand on the tongue while lifting the body of the trailer to take advantage of the weight of the operator in standing up the trailer. The limitations come as the mass of the trailer increase and the operator is no longer able to lift the trailer into the vertical position. In addition the tongue structure could be quite heavy and difficult to raise into the stored position. In fact most of the other prior art in this field relies on human power to lift the trailer into the vertical position.
A winch arrangement such as in U.S. Pat. No. 5,924,836 makes the stand up procedure very easy. But in this configuration, the load bearing surface in front of the trailer wheels must be made to have a “double joint” that would increase complexity and reduce the strength because of the reliance of pins or connectors to keep the load bearing section together during use.